Rotary thread-rolling machine



R, H, 5mm

ROTARY THREAD ROLLING MACHINE Filed July 14. 1921 4 Sheets-Sheet 1 Jan. 15, 1929,

' R. H. SMITH ROTARY THREAD ROLLING I ACHINE Filed July 14. 1921 4 Sheets-Sheet 2 Jan. 15, 1929.

R. H. SMITH ROTARY THREAD ROLLING cums Filed July 14, 1921 q sheets-shaet R. H. SMITH ROTARY THREAD ROLLING CHINE Jan. 15, 1929.

Filed July 14. 1921 4 Sheets-Sheet 4 PITZU 67173 zz- 0 Patented Jan. 15, 1929.

PATENT OFFICE.

BOY E. SMITH, OF KENT, OHIO.

ROTARY THREAD-ROLLING MACHINE.

Application filed July 14, 1921.

This invention relates to a rotary thread rolling machine and has for its chief object to provide a. thread rolling machine for rolling threads on bolts and screws which is rapid in operation and which produces a thread which is uniform and of superior quality.

One of the more specific objects is to provide a thread rolling machine, so constructedthat the blanks may be fed to it automatically, and a second but very important object is to provide a construction which compensates for varying sizes of blanks.

The invention may be briefly summarized as consisting in certain novel details of construction, and combinations and arrangements of parts which will be described in the. specification and set forth in the appended claims.

In the accompanying sheets of drawings showing a construction which answers the requirements very effectively, Fig. 1 is a side view of the machine; Fig. 2 is an end view of the same; Fig. 3 is a top plan view;

Fig. 4 is a fragmentary sectional view substantially along the line 44 of Fig. 2, looking in the direction indicated by the arrows; and Fig. 5 is a view partly in elevation and partly in'section, the parts in section being along the line'55 of Fig. 3, looking in the direction indicated by the arrows.

In the drawings, 10 represents a bed carrying a casting 11 provided with bearings for an upper horizontal shaft 12 which in this instance is adapted to be driven by a belt pulley 13, althou h, of course, it may be otherwise driven. his shaft, which is of fairly large diameter, carries atone end a rotary threader 14 whose periphery is threaded so that by the co-operation of a threaded relatively stationary threader, the threads may be rolled on bolts and the like. This rotary threader 14 is removably but tightly secured to the end of the shaft, and in this instance it is clamped onto a tapered portion 12 by a clamp 15 and a nut 16 which is screwed onto a reduced threaded end of the shaft.

Arranged adjacent, and co-operating with the rotary threader 14 is a non-rotating arc-shaped threader 17which is arranged adjacent the periphery of the rotary threader 14 surrounding about 90 of its periphery. As will be understood by reference to Figs. 4 and 5 particularly, there Serial No. 484,572.

is a space or clearances, between the rotar and stationar threaders, so that the bla may be intro uced between the two, and by the relative rotation of the threaders will be rolled between the contiguous surfaces so that the threads corresponding to the threads cut on the surfaces of thetwo threading members will be rolled into the shank of the blank.

The non-rotating threader 17 is not fixed in position, but in accordance'with an important part of the invention has a mounting such that it is capable of compensating for blanks of different sizes, by a slight rocking motion, and this part of the invention will now be described. It will be observed particularly from Fig. 5, that the threader 17 is secured by clamps 18 to a substantially L-shaped threader holder 19 .which is pivotally mounted at a slightly offcenter point with respect to the ends of the holder 19 on a transverse pin 20 carried by an adjustable carrier 22 also substantially L-shaped, and adjustable in and out on a line passing through the center of the shaft 12 and pivoting pin 20. In this instance this carrier is rovided with elongated slots 22 through wli ing pins 23 projecting from one end 0 the casting 11. For the purpose. of adjusting the carrier 22, and also to assist in supporting it, a casting 24 secured to the casting 11 has an outstanding arm 24 which is provided with an adjusting bolt 25 in line with the center of the pin 20 and the center of the shaft 12, as shown in Fig. 5, this bolt having its inner portion extending into the threaded socket of a boss 22 on the outer side of the carrier 22. By turning this bolt 25, the carrier 22, non-rotating threader 17 and threader holder 19 can be moved as a unit toward and from the rotary threader 14 so as to adapt the machine for difierent sizes of bolts to be threaded. It will be understood, of course, that different sets of threaders 14 and 17 will be used and to render this compensating effective I provide for the purpose of governing the rocking movement of the holder 19, two abutich pass guide and sup ort- 85 ments 26 and 27 which are carried by the carrier 22 and engage arms or portions of the holder 19 on opposite sides of apivoting pin 20, these abutments 26 being in this instance at right angles to each other, and the portions of the holder 19 which they engage being likewise at right angles to each other. tionary, but an adj ustable bolt against which the upper arm ofthe. holder 19 engages to limit the width of the arc-shaped slot S between the threaders at the entrance end thereof. The other abutment 27 consists of the end of a yieldab-le plunger 27 which is pressed inward by a powerful spring 28 hearing between the base of a cup formed in the plunger and an adjustable cap 29 closing the end of a socket 30 of the lower arm of the carrier 22. I

Before describing the effect of this pivotal holder and the fixed and yieldable abutments bearing on opposite ends thereof, I

will take up an important adjunct of the machine consisting of an automatic feeder by Which'the blanks are automatically supplied to the threaders. In this instance the blanksare fed from a hopper '31 which is supported at the top of the machine on the bearings of casting 11 for shaft 12. In this hopper a rotary feeder in the form of a starwheel 32 is mounted, and this feeder is turnedstep by. step by a pawl 33' engaging with a ratchet 34 on the end of shaft 35 on which the feeder 'is secured. In this instance the pawl is moved back and forth by a plunger 36 having at its inner end a roller ber 40, the function of which is to discharge from the chute the blanks which lie crosswise and not vertically in the chute, this kick-out being adapted to be driven by a belt, not shown, passing about a sheave 41 on the shaft 12, about a guide sheave 42 and a driving sheave 43 on the shaft carrying the kick-out 40, the sheaves 42 and 43 "and the kick-out being supported 011 the hopper.

The lower end of the chute 89 terminates just above the threader 17 and holder 19, as best shown in Fig. 5, and between the lower end of the chute and the holder 19 is a fiat feeder blade 44 which reciprocates back and forth in a horizontal direction and has a stroke suflicient to move the blanks one at a time from the lower end of-the chute to the arc-shaped space or slot between the threaders, and, in fact, into one of a series of transverse receiving notches 14 of the rotary threader. In this instance I have The abutment 26 is a normally 'staprovided three of these notches 14 arranged 120 apart, and the feeder blade 44 is so timed that it makes three forward strokes during each revolution of the shaft 12 and rotary threader 14, and at each forward stroke push a-blank across the top of the threader holder 19 into one of the notches 14 so that it then can be carried down into the space between the threaders and rolled between them so as to be threaded. In this instance the feeder blade 44 is operated by a three-point cam 45 carried bythe 'shaft 12 just inward of the rotary th'reader 14, and at its peripheryis engaged by a roller 46 on the inner end of an endwise movable plunger 47 carried by a bracket 48 attached to a slide 49 to which the feeder blade "44 is secured, the slide working in a guide on an extension of the carrier 22. A spring 50 surrounds the plunger 47"a'nd keeps the roller in contact with the surface of the cam The'operation is as follows: The carrier 22 will be properly set for the size of blank to be threaded, and the setting is such that the largest over size blank (i. e. which may be a'few thousandths over-size) will be able to pass between the rotary and non-rotating threaders at the point A of the passage or space S, this point being on a line between the center of the pivoting pin 20 and shaft 12 and therefore at a point where there is no variation in the width of the passage S, due to rocking of the die 17 and its holder 19; Likewise the normally stationaryabutment 26 will be so'a'djusted that'the width of the space or passage S atthe top or entrance end thereof will be such that the blanks will enter the space and immediately start rolling,'it being understood that the space S is somewhat wider at its entrance end than at its discharge end.

If the blanks happen to be of the correct size or diameter, they will be fully threaded at or about the point B (Fig. 5) the threads being simply smoothed during the remainder of the travel through the passageS If, the blanks are slightly over size they will be fully threaded at a point between thepoints marked A and B, and if they areslightly under size they will be fully threaded at some point beyond the point designated B.

-However, the threads will be uniformre- 'gardless of whether the blanks are a few thousandths over size or under size, and the threads will all be smoothand of good quality, for as the larger blanks pass through the end portion and therefore narrower part of the space or passage S, the die 17 and its holder 19 are rocked by the passage of the now threaded blanks, slightly widening the passage S at 1ts discharge end, and moving the upper end of the die'17 inward slightly. This, however, has no effect on the receiving ofthe blanks in the space between the threaders, or the initial rolling action, for though a blank is admitted between the threaders while th preceding blank is still between the threaders, the slight inward rocking of the upper end of the threader 17 has simply the effect of causing a somewhat deeper initial cutting by the cutting threads at the start of the threading operation.

It will be observed by reference to Fig. 5, that the centers-of the points or raised portions of the cam 45 are midway between the notches l4 of the rotary threader id, and in consequence immedlately after a blank has been inserted in one of these notches, the cam begins to retract the blade, and as the forward end of the blade moveis beyond the slot of the chute 39, the lower most blank drops down on the carrier 19 in front of the blade, and shortly after this occurs the cam permits the spring 50 of the feeder to move the blade inwardly, and just before the next notch 14* comes opposite the path of movement of the blade 44, the latter moves a blank up against the rotary threader, and immediately after it enters the notch 14 itis carried downward into the threaded space S and is rolled between the threaders, and then as it rolls down through the space S its threads are rolled thereon, the lower part of, the threader l7 yielding if necessary, and it is discharged. from the machine fully threaded. As it is passing through the space S the next notch 14 approaches the receiving position, and the blade 44 moves the next blank in a sim' lar manner to that described into the notch 14 and the operation is repeated.

As already explained, the rocking of the threader l7 and its holder 19 as the relatively large sized blanks pass through, prevents the elogging of the'threader and allows all blanks to be properly and uniformly threaded.

Having described my invention, I claim:

1. In a machine for rolling threads on bolts and the like, a pair of co-operating thread rolling members adapted to receive blanks between them, one of said members being rotatable, and having in its periphery a plurality of blank receiving portions regularly spaced circumferentially thereof and the other member being oscillatory about a point between its ends. \r

2. In a machine for rolling threads on bolts and the like, a'pair of co-operatin thread rolling members including a pivoted threading member and a rotary threading member provided on its periphery with a blank receiving portion, means for rotating the rotary member, and means for automatically feeding blanks to the blank receiving portion of the rotary member so that they will be received one at a time by, and rolled between the threading members.

3. In a machine for rolling threads on bolts and the like, a pair of co-operating thread, rolling members including a member adapted to oscillate about a polnt between its ends and a rotary member between which blanks are adapted to be rolled so as to be threaded, the rotary member having at its periphery a plurality, of equally spaced transverse blank receiving portions, means for rotating said rotary member, and means operating in timed relation to the rotation of said member for automatically feeding blanks so'that they will be received in said portions and carried between the co-operating threading members.

4. In a machine for rolling threads on bolts and the like, a pair of co-operating thread rolling'members including arotating threading member and a normally stationary threading member arranged adjacent a portion of the periphery of the rotary member, said normally stationary member being yieldingly mounted so that it may compensate for blanks of different thicknesses rolled between the members, .a support for said yieldably mounted member, and means for bodily adjusting said support toward and from the rotating threading member.

5. In a machine for rollin threads on bolts and the like, a'rotary t read rolling member, a normally stationary thread rolling member arranged adjacent the periphery of the first named so that blanks may be rolled between the two members, said normally stationary member being pivotally mounted to oscillate about a point between its ends, and means yieldably resisting the movement of the stationary member about its pivot to permit the rolling of blanks varying in diameter.

6.-In a machine for rolling threads on bolts and the like, a rotary thread rolling member, a normally stationary thread rolling member arranged adjacent the periph ery of the first named so that blanks may be rolled between the two members, said normally stationary member being movably mounted, a spring for resisting movement of the discharge end portion thereof,'but serving to permit said end portion of said member to yield to adapt the machine for blanks varying in sizes, and a fixed abutment engaging said stationary member adjacent the receiving end-thereof.

7. In a thread rolling machine, a rotary thread rolling member, a normallystationary thread rolling member arranged adjacent the periphery of the first named and spaced therefrom so that blanks may be rolled between the two, and a carrier for the stationary member to which the latter is pivoted between its ends, said carrier being adjustable bodily toward and from the rotating member.

8. In a thread rolling machine, a rotary ary thread rolling member arranged adjacent the peri hery of the first named and spaced there rom so that blanks may be rolled between thetwo, a fixed carrier for the stationary member to which the latter is pivoted between its ends, and a spring for yieldingly opposing the movement of the member about its pivot to widen the discharge end of the space between the two threading members so as to compensate for blanks varying in diameter..

'9. In a machine for rolling threads on bolts and the like, a rotary threading member, an arc-shaped normally stationary threading member arranged adjacent the periphery and forming a space for the passage of blanks as they are rolled between the two threading members, a holder for said normally stationary threading member pivoted between its ends, and a pair of abutments engaging the holder on opposite sides of its pivot, one of said abutments being normally fixed, and the other being yieldthreading member arranged adjacent the periphery and forming a space for the passage of blanks as they are rolled between the two threading members, a holder for said normally stationar threading member pivoted between its en s, and a pair of abutments engaging the holder, one of said abutments being fixed and limiting the widening of said space at the entrance end thereof, and the ot 161 abutment being yieldable and permitting the widening of said space at the discharge end thereof.

11. In a machine for rolling threads on bolts and the like, a rotary thread rolling member, a normally stationary thread rolling member arranged adjacent the periphery of the first named and forming an areshaped passageway through which blanks are adapted to be rolled, an adjustable carrier for said second vnamed threading member whereby the normal width of the passageway may be varied, .said second threaded member being mounted for rocking move ment, and means acting thereon to permit said second member to yield on the passage of an over size blank through the passageway.

In testimony whereof, I hereunto aifix my signature.

- Y ROY H. SMITH 

